Decorticating method and apparatus



s. L. sT. JOHN 2,244,971

Filed July 21, 1959 7 Shets-Sheet 1 June' 10, 1941.

DECORTICATING METHOD AND APPARATUS NA a Jg luesterL.5tJ0hn AT RNEY June 1 s. L; s'r. JOHN DECORTICATING METHOD AND APPARATUS Qty/ esta? I St Jo/m AT RNEY June 10, 1941. s, 5 JOHN 2,244,971

DECORTICATING' METHOD AND APPARATUS Filed July 21. 1939 7 sheets-snet s W h w u 2 w r 6 a M 9.

AT RNEY June 10, 1941. s. L. ST. JOHN I DECORTICAI'ING METHOD AND APPARATUS Fild July 21. 1939 7 SheetsSheet 7 INVENTOR 'yhkesterLStJhn BY' I 74/%z,

- A ORNEY Patented June 1 0, 194! I Sylvester L. St. John, Mansfield, Mass.

Application min, 1939, Serial No. 285,640

37 Claims.

The invention relates to method and means for decorticating ramie (Urtica. nivea) and other fiber bearing plants.

The strength, luster, and other qualities of ramie which make it desirable for many purposes have long been recognized. It is also well known that ramie can be grown successfully in the Gulf Coast States, thus ofiering a promise of profits to the grower as well as to the manufacturer. In recognition of these favorable circumstances, large sums of money have been expended in attempts to establish a ramie industry in this country. These enterprises have not been successful, however. Probably'one of the chief reasons for their failure has been the difiiculty and expense of separating the fiber from the stalk. In China, the ribbons containing the fiber are stripped from the stalk and scraped by hand, producing what is known as China-grass. In order to compete successfully with imported China-grass, it appears to 'be necessary to perfect a low-cost mechanical method of separating the fibers from the stalk.

The problem thus presented has attracted much attention, and many attempts have been made to perfect a machine capable of performing the stripping operatibfi. .These attempts have not been attended with any substantial degree of commercial success, however. One method which has been devised consists in running the stalks through serrated or corrugated rolls to break up the woody portion of the stalk, after which the wood is separated from the fiber by passing the stalk through or over a beater. The corrugated rolls of such a machine injure the fiber, however, and may even out much of the fiber into short lengths, which is undesirable and reduces the value and utility of the product. Other methods fail to eflfectsufiiciently complete separation of the woody portions, or fail to act on the entire length of the stalk so that the butt-ends pass through the machine without being acted on by the beater. It is an object of my invention to provide a. method and means for mechanically separating the fiber from the rest of the stalk which will overcome these and other disadvantages of methods heretofore de vised.

A general object of my invention is to provide A further object of the invention is to provide decorticating apparatus which is inexpensive to operate, and which efi'ects more complete separation of the fibers and woody matter.

Other objects and advantages will appear as the description proceeds.

In the drawings I have illustrated certain preferred embodiments of the apparatus aspects of my invention. Fig. 1 is a side elevational view of one form of apparatus, showing the general-arrangement thereof and the progress of a stalk of ramie through the machine. Fig. 2 is a plan view of the e apparatus.

Figs. 3 and a are enlarged detail views of a portion oi the same apparatus, illustrating the crushing rolls, reed rolls, and breaker bars, Fig. 3 being a side elevational view and Fig, 4 a fragmentary plan View of these elements.

Figs. 5 and 6 are enlarged vertical sectional views taken, respectively, .on the lines 5-5 and 6-t of Fig. 2.

Fig. 7 is an elevational view of the operating mechanism for the rolls and breaker bars, taken as indicated at ili of Fig. 1.

Fig. 8 is a side elevational view of another form of apparatus embodying the invention.

Figs. 9, 10 and 11 are detail views illustrating a modified form. of mounting for the fixed breaker bar, providing a clearance adjustment between it and the movable breaker bar. Figs. 9 and 11 are plan and elevational views, respectively of this detail, and Fig. 10 is is'iio rlzontal sectional view taken on the line ill-m of Fig. 11.

Fig. 12 is a. greatly enlarged cross-section of a ramie stalk. I

The present invention is applicable to the decorticating of the stalks of many varieties of bast fiber plants. Among these may be men- .tioned hemp (Cannabis sativa) jute, flax, caroja,

kenaf, and kendyi. Generally speaking it is probably applicable to all best fiber plants as dis- 1 tinguished from the agaves which have the fiber in the-center of the leaf instead of in or adjacent the bark of the stalk- I have found it to be particularly effective in the treatment of ramie and hemp. In view of the problem which has existed in connection with the establishment of a profitable ramie industry in this country, and which apparently has its crux in the provision of some inexpensive-mechanical decorticating operation, I shall describe the invention with particular reference to processing of the ramie.

The name ramie as used herein and in the appended claims is intended to include the various members of the family Urticacae, of which the two principal species are Boehmeria nivea or Urtic'a m'vea which has a white under-leaf, and Urtica utilis, which has a green under-leaf. The Urtica is the more important plant, and is theone which would be expected to form the backbone of the ramie industry in this country. A

- cross-section of a ramie stalk, greatly enlarged,

is shown in Fig. 12. -The stalk comprises a pith center I surrounded by *a layer of woody (fibro elongate the woody center portion and strip, or'

partially strip, it from the fiber and the bark to which the fiber is attached; second; bending the stalk first in one direction and then in another to break up the woody portion without breaking or weakening the fiber; third, beating or combing out the woody fragments or hurd; and fourth, removing the bark from the fibers and softening the latter by passing the remainder of the stalk, through fluted or grooved rolls under relatively low pressure. tant feature of this method resides in stripping or loosening the woody portion of the stalk from the bark and fibers before any substantial bending, or sharp bending, of the fibers takes place. Another feature resides in. substantially entirely removing the woody matter before completing separation of the fibers from the bark. Still another feature resides in pulling the'ends of the stalks through the bending means in such a manner as to effect complete decortication of theentire length of stalk;

With reference to Figs. 1-7 of the drawings I shall now describe a preferred form of apparatus for carrying out my novel method. The several units for carrying out the four principal steps described are indicated generally by the reference characters 5, 6, I and 8 in Fig, 1. In each vcase the arrow from the reference character frame members 9, and a second pair of frame members l may be provided to support the end of a conveyor to carry away the separated fibers. The frame members 9 and III are tied together in any convenient manner, as by means of tie rods II. If desired, the various frame members may be mounted on a base plate or truck chassis for ease of transportation from one point of operation to another.

Mounted on the frame members 9 are the frames l2 of roll stand 5, provided with vertical guides or ways 13 (Fig. 3) in which are slidably mounted bearing blocks [4 for the axles is of the rolls IS. The pressure on the stalks passing through the rolls I6 is regulated by a pair of screw-downs l1 which'vary the compression of I porting lugs l9 by the studs2l.

An imporbearing blocks I4.

The frames H are provided with lugs I3 to support the guide plate 20 which is provided with depending lugs for attachment to the sup- The guide plate 2| may be flanged, as at 22, to provide a connection to the feed table 23 which rests at one end on the angle 24 attached to the flange 22 by cap screws 25. The feed table 23 is provided with guide rails 26 along each side thereof, and with a series of guide members 21 evenly spaced across its width. The guides 21 preferably'consist of inverted U-shaped wire staples arranged as indicated in Figs. 1 and 2, and presenting no sharp arrangement the stalks, when thrown on the a thickness of stalks at the slots of the breaker bars to be described.

An extension 28 formed as a part of each of the frames I2 provide supports for the breaker bar unit 6 and for the associated trumpet guide and feed rolls. To the edges of the extensions 28 are secured brackets 29 by means of cap screws 30. Portions of the brackets 29 project upwardly of the frames [2 to form supports for the fixed breaker bar or plate 3| and guides for the movable breaker bar or plate 32. For the latter purpose, the brackets 29 are notched at 33 (Fig. 4) providing guiding channels between the fixed breaker bar 3| and portions of the brackets 29. The fixed breaker bar 3| is secured to the brackets 29 by means of bolts 36, or in any other convenient manner. The breaker bars 3| and I 32 are provided with slots 35 and 36, respectively,

' at the center of its travel.

extending laterally of the machine. The slot 36 in the movable breaker 'bar lies opposite the slot 35 in the fixed breaker bar when the former is The form of the slots 35 and 36 is best shown in Fig. 5.v It will be observed that these slots are rounded, or tapered, in the direction of travel of the stalks 3'i. The surfaces 38, 39, which form the taper toward the exit sides of the slots, are of greater extent than the rounded, or tapered, surfaces at the entry downwardly against the lower tapered surface 39 of the breaker bar 3|. Thus the stalks are bent first in one direction and then in another in a manner which breaks up and further loosens the woody portions of the stalks without cutting or injuring the fiber to any extent. In Fig. 5, the breaker bar 32 is shown at the limit of its upward travel. At the limit of its downward travel,

the center-line of the slot 36 will be separated vertically from the center-line of the slot 35 by a distance which is equal in extent but opposite .in direction to that shown in Fig. 5. The'top the fibers. These rolls 42 should be located as close as possible to the breaker bar 2|, and are of relatively small diameter in order to bring theircenter-lines in proximity to the slot 85. The proximity of these rolls to the breaker bar 3| has the advantage of feeding the stalks all the way through the breaker bars while holding them firmly up to the very end thus insuring complete decortication of the entire length of stalk. Screwdowns 48 in coniunction'with compression springs 44, hearing against the upper bearing block 4|, provide means for resiliently regulating the pressure between the rolls 42. To assist in guiding the stalks between the crushing rolls I6 and feed rolls 42, it is preferable to employ a guide trumpet 45. As shown, this consists of a table 45 having depending lugs 41 at either end for attachment to the brackets I2, as by means of screws or bolts 48. At its ends, the table is provided with upstanding flanges to which a cover plate 48 is removably attached, as by means of screws 50 (Figs. 2 and 3).

The heater unit 1 and bark removal unit 8 may conveniently be carried by brackets or extensions 52 mounted on the frames 8. The beater unit comprises a pair of circular discs 52 mounted on a shaft 54 journaled in the brackets 52, said discs carrying beater bars 55 around their periphery, these bars conveniently being constructed of angle-irons one leg of which is welded to the edges of the discs. 53 and the other leg of which extends radially to flay the hurd from the bark and fiber when thebeater is rotated.

The bark removal and fiber softening unit 8 will be described principally with reference to has been substantially entirely removed from the stalk, such grooved or serrated rolls, operating under relatively low pressure compared to the crushing rolls, do not injure or weaken the fibers .0 any substantial extent, if at all. I prefer to employ at least four stands of barkremoval rolls.

the grooves in the rolls should have rounded :dges such as would correspond in form to the iurface of an ordinary corrugated sheet (see Fig. 6). I have found this unit to be particularly effective if some of the rolls are grooved longitudinally and others spirally. Thus the rolls 56 and 59 are grooved longitudinally, whereas the rolls 51 and 58 are grooved spirally. The spirals of the grooves of the rolls-51 and 58 are equal in pitch but opposite in direction. This arrangement of rolls hasthe effect of bending the bark both up and down, and from side to side, which is most effective in separating the bark from the fiber. The axles of the rolls are carried in bearing blocks 60 slidably mounted in ways 6| formed inframes 62 secured to the brackets 52 by screws or bolts 63. Screw-downs 64 having threaded engagements with the frames 62, or with members associated therewith, regulate the compression of coil springs 65 bearing against theupper pairs of bearing blocks 60. The roll passes are regulated by adjustable stop members 66 (Fig. 1) which may have a screw-threaded engagement with one of each set of opposed bearing blocks and abut the other block of the set, as at 61. The steps 66 may be provided with lock-nuts 68 to hold themin adjusted position. Guide members 68 and are mounted on the bases of the frames pulley 11 through a belt 18.

the stock from the last roll stand 5! onto a com veyor belt 1I. The conveyor belt II runs over a roller 12 journaled in brackets 18 secured to the frames II. I d

Having described the various operating units of my machine, I shall now describe the driving mechanism therefor, although it should be understood that I do not limit myself to the particular driving means shown, these means being disclosed merely by way of illustration. A motor 14 is mounted on a base plate 15 which may conveniently be secured to the tie rods II of the frames 8. The pulley 16 of this motor drives a keyed to a main shaft 10 journaled in the frames 8. The crushing rolls I6 are driven from the main shaft 15 as follows: from sprocket keyed to main shaft 18, to sprocket chain 8 I to sprocket 82 keyed to shaft 83'; from pinion 84 keyed to shaft 88 to gear 85 keyed to shaft 86; from pinion 81. keyed to shaft 86 to gear 88 keyed to shaft of the lower crushing roll I6. The upper crushing roll is driven from the lower crushing roll by gear 88 and 50 secured to the roll shafts at the opposite side of the machine. The shafts 83 for v the sprockets and gears 82 and 84 may be adjustable in order to permit gear changes for varying the speed of the crushing rolls as may be desired for processing different plants or stalks of different size or decorticating characteristics. For this purpose I mount the shaft 83 in arcuate slots 9| (Fig. 1), having the axis of the shaft 18 for a center. This permits changes in'the center-to-center distance between shafts 83 and 86 to accommodate different gear sizes. The lower feed roll 42 is driven from the shaft I5 of the lower crushing roll I6 through a gear 93 keyed to said shaft, idler gear 94, and pinion 55 keyed to the shaft of the lower feed roll 42. The upper feed roll is driven from the lower feed roll through I pinions 86 and 81 keyed to the feed roll shafts at the opposite side of the machine.

The movable breaker bar 32 is driven from the main shaft 19 through eccentric straps 88 cooperating with eccentric cams keyed to the shaft 18L The eccentric straps 88 are connected to the breaker bar 32 by rods 88, bolted to the bar at I00, and having a clevis IOI secured to the lower end thereof to pivotally receive the ends of the strap 98. The strap and clevis are joined by a pivot pin I02. The rods 98v are guided in brackets I03 secured to the frames 9 by screws or bolts I04. The eccentric mechanism imparts a rapid vertical reciprocation to the breaker bar 32 of the extent previously set forth.

The heater I is driven from the main shaft 18 in any suitable manner, as by means of the belt I05 and pulleys I06, the shafts 18 and 54.

The bark removal unit 8 may be driven directly from the crushing roll shaft I5 by a chain and sprocket I08, I09, the chain I08 having a driving engagement with a sprocket IIO keyed to the shaft of the lower roll 56. The upper roll 56 is driven from the shaft of the lower roll 56 by gears II I, I I2 keyed to their respective shafts. The succeeding roll stands 51, 58 and 58 are driven from the shafts of the stand 56 by sprockets and chains II3, II4. Thechain II3 engages sprockets keyed to the shafts of each of the lower rolls 56, 51, 58 and 58 at one side of the'machine; and the chain II4 engages sprockets keyed to the shafts of each of the upper rolls 56, 51, 58,

I01, secured respectively to 62, guide 68 directing the stock from the beater intothe first roll stand 56, and guide 10 directing The pulley 11 is rollsv I6; feed rolls" 42,, and rolls '56 are, substania y" h fl m i fl w c' he r e a." m

e'rably are adjusted "to rupfat a very slightly. greater peripheral speed thanthe crushing rolls,

to 'take up the elongation of the fiber due to crushing and .to' insure that there will not, be any appreciable amount of slack between these two sets of rolls. The peripheral speeds of the remaining stands of rolls 51, 58, and 59 are progressively higher. This speed differential produces a scraping or stripping action On the bark and removes any hurd remaining after the flailing performed by the rotary beater I. The clearances between the rolls of the stands 56, 51, 58 and 59, as regulated by the adjustable stops 66, prevent tearing or injury to the fiber.

The peripheral speed should be adjusted in accordance with the size and character of the stalks to be decorticated. In general, the larger the stalk diameter the slower is the optimum speed. I have found that for ramie, speeds ranging from 95 to 125 inches per minute can be em ployed with good results. Depending on the conditions encountered, the peripheral speeds may be higher or lower than this, however. Hemp can be run through much faster than ramie; jute somewhat slower.

The speed of reciprocation of the breaker bars should be so related to the peripheral speed of the crushing and feed rolls as to flex or bend the stalk (in the case of ramie) at intervals preferably not greater than inch apart; that is, not.

greater than A; inch between successive downward bends or between successive upward bends. I have found thatwhen this condition is maintained, the hurd can be advantageously removed by the flailing operation.

The delivery belt II is driven from the shaft 54 of the beater unit by a belt II5 engaging pulleys H6 and III secured, respectively, to theshaft 54 and shaft II8 of the roller I2 which frictionally engages the belt 'II. The roller at the other end of the belt II (not shown) may be driven by' a belt II9 from a pulley I28 keyed to the shaft IIB.

In Fig. 8 I have illustrated another embodiment of apparatus suitable for carrying out my novel method. In this form of apparatus the construction of the various units 5, 6, 'I and 8 may be essentially the same as described with reference to Figs. 1-7 inclusive. Like reference numerals have been placed on the similar parts of thetwo machines. The principal modification which has been made in the machine shown in Fig. 8 concerns the matter of arranging the various units so that the material is fed below the beater 1 instead of above it. The change in the arrangement can best be seen from comparison of Fig. 1 with Fig.- 8. Fig. 8 is taken from the opposite side of the machine and thus shows up more clearly some of the features previously described in connection withFig. 1, such as the' arcuate slot 9|. This view also shows a vertical slot I2I which permits a change in the position of the journal for the shaft 86, carrying the gear 85 which is the one designed to be interchanged to modify the speed. lt should'be observed that eam jr gitransy rsely "ofilthe machine; The cueuz s er s an d in the w ve erb lt 1 carried by'.brack 'e t s I25 mounted on. the frames secured, respectively, to the frames 62 of the unit 8 and the frames 9. The belt I21 may be made of wire cloth or other foraminous material such as will permit the hurd fragments to fall there- .through as they descend from the beater I. The belt I21 is driven from the roller I28 which in turn is driven by a belt I35 passing around a pulley I36 fastened to the shaft of the lower roll 56 of the unit 8.

The driving means for the various units of the embodiment shownin Fig. 8 are the same as have been described with reference to Figs. 1-7 except as now will be noted: The heater 1 is driven from the main shaft I9 as before, but the drive is through a crossed belt I32 so that the direction of rotation of the beater will be reversed. Also, inasmuch as the conveyor belt II is driven from the shaft 54 on which the beater I is mounted, it be- I24 jwhi'ch'jtake the throw the hurd fragments downwardly, and they are permitted to fall by gravity from the side and bottom of the beater instead of having to find their way downwardly from the top of the beater.

In Figs. 9, 10, and 111 show a modified mounting and guide for the fixed and movable breaker bars. Fig. 9 is a view similar to a portion of Fig.-

4 in which the bracket 29 has been replaced by a bracket I31 secured by bolts or screws 38 to the extensions 28 of the frames I2. The fixed breaker bar ,3I is secured to the brackets I3l by bolts I38 which pass through apertures in the brackets and have a threaded engagement with the breaker bar. The brackets I31 are provided with notches of a different form than the notches'33 of the brackets 29. In the modified construction I these notches are provided with inclined surfaces I39 "for cooperation with correspondingly inclined surfaces I48 of the reciprocable breaker bar I. This construction affords a lateral guiding support for the bar I 4| while permitting a suitable clearance between the bracket and the bar. In order to provide an adjustment for the clearance between the breaker bars 3| and I,

set screws I42 are provided in the brackets I3'I so that when the bolts I38 are loosened, the set screws can be advanced to provide the desired r amount of' clearance at I". This construction is applicable to the breaker bar unit of both the machine illustrated in Figs. 1-7 and that iilustratedinFig. 8. I

Although I have shown the use of only two breaker bars in combination, it will be understood that the number of such bars may be increased if desired. For example, it would be possible to use a plurality of breaker bars with successively wider slots. These breaker bars provide means for bending the crushed stalks of the plants up and down, or back and forth, in such a way as to break up the woody interior portions of the stalk the bark which contains the fiber before any bending action is performed, thus avoiding the cutting or weakening of the fiber which results from crushing it between grooved or corrugated pressure rolls, and making it possible to produce long-line fiber. When the crushing operation is performed with smooth-surfaced rollers, the stalk is maintained substantially straight up to the zone of maximum pressure. Thereafter, it is bent back and forth without any tendency to break the fiber which, along with the bar, has already been loosened from the woody portion. Having in mind the essential features of my method and apparatus, it will be understood that various modifications can be made while retaining important advantages of my invention. For example, in place of the single machines which I have described specifically, duplex or multiple machines can be employed, thus increasing the width and capacity of the combined machine. Also, the form of the rotary beater is subject to considerable variation while retaining the essential principle of operation thereof. Again, the unit 8 may be designed with a smaller or greater number of roll stands than I have shown in my preferred embodiments. Other modifications will suggest themselves to those concerned with the problems presented in the decortication of bast fiber plants. The embodiments which I have ,described have been designed with specific reference to the problem of decorticating the Urtica m'vea. For the decortication of other varieties of best fiber plants, it may be found desirable to make certain alterations in the proportions and arrangement of the various elements, but the general principle of operation will remain the same. The terms and expressions which I have employed are used as terms' of description and not of limitation, and I have no intention of excluding such equivalents of the invention set forth, or of portions thereof, as fall within the purview of the claims.

Iclaim:

1. Method of decorticating bast fiber plants which comprises applying crushing pressure transversely of the stalk without bending the stalk and before the stalk has been bent sufllciently to produce substantial transverse fractures of the woocLy portion thereof, 'and thereafter bending the stalkback and forth in the absence of crushing pressure the crushing pressure being discontinued priorto the bending step;

2. Method of decorticating. bast fiber plants which comprises applying crushing pressure to the stalk without bending the stalk and before the stalk has been bent sufilciently to produce substantial transverse fractures of the woody portion thereof, thereafter bending the stalk in the absence of crushing pressure, the crushing pressure being discontinued prior to the bending step, flailing the stalk, and separating the bark from the fiber.

3. Method of deoorticating bast fiber plantswhich comprises applying crushing pressure to the stalk withoutbending' the stalk and before 'the stalk has been bent sufliciently to produce substantial transverse fractures of the woody portion thereof, thereafter bending the stalk back and forth in the absence of crushing pressure, the crushing pressure being discontinued prior to the bending step, flailing the stalk, and bending the bark and fiber back and forth under pressure. v

4. Method of decorticating bast fiber plants which comprises applying crushing pressure to the stalk without bending the stalk and before the stalk has been bent sufliciently to produce substantial transverse fractures of the woody portion thereof, thereafter bending the stalk back and forth in the absence of crushing pressure, the crushing pressure being discontinued prior to the bending step, flailing the stalk, and

bending the bark and fiber up and down and from side toside under pressure.

5. Apparatus for decorticating bast fiber plants which comprises smooth-surfaced pressure rolls for crushing the whole stalk without bending it, reciprocatory means independent of the rolls for initially bending the crushed stalk and means for flailing the stalk as it issues from the bending means.

6. Apparatus for decorticating fiber plants which comprises means for applying crushing pressure to the straight stalk without bending it, reciprocatory meansindependent of said pressure applying means for initially bending the crushed stalk and means for flailing the stalk as it issues from the bending means.

7. Apparatus for decorticating bast fiber plantsit,reciprocatory means for initially bending the crushed stalk back and forth in the absence of crushing pressure, and means for flailing the stalk as it issues from the bending means.

8. Apparatus for decorticating bast fiber plants which comprises means for applying crushing pressure to the straight stalk without bending it, means for bending the crushed stalk back and forth in the absence of crushing pressure, and means for bending the bark back and forth under pressure to separate the fiber therefrom.

9. Apparatus for decorticating bast fiber plants which comprises means for applying crushing pressure to the straight stalk without bending it, means for bending the crushed stalk back and forth in the absence of crushing pressure, means for flailing the stalk as it issues from the bending means, and means for bending the bark back and forth under pressure to separate the fiber therefrom.

10. Apparatus for decorticating bast fiber plants which comprises smooth-surfaced crushe ing rolls, rough-surfaced rolls, reciprocatory means therebetweeir for bending the crushed stalk back and forth, and means for feeding the stalk into the crushing rolls in a straight line and for maintaining it in a straight line until it reaches the reciprocatory means.

11. Apparatus for decorticating bast fiber plants "which comprises stalk-crushing means, a pair of plates having openings through which the crushed stalk is arranged to pass, means for reciprocating one of said plates with respect to the other to bend the crushed stalk back and forth, and means for feeding the stalk into the crushing rolls in a substantially straight line and for maintaining it in a straight line until it reaches the plates.

12. Apparatus for decorticating bast fiber plants which comprises a pair of smooth-surfaced crushing rolls, .a pair of plates having openings I therethrough arranged at the exit side of said rolls, means for producing relative reciprocation of said plates in a direction to vary the alignmerit of said openings with respect to the pass of the crushing rolls, and means for feeding the stalk into the crushing'rolls in a substantially straight line and for maintaining it in a straight line until it reaches the plates.

13. Apparatus 'for decorticating bast fiber plants which comprises a pair of smooth-surfaced crushing rolls, a pair of plates having openings therethrough arranged at the exit side of said rolls, means for producing relative reciprocation of said plates in a direction to vary the alignment of said openings with respect to the pass of the crushing rolls, and means for feeding the plant stalk in a substantially straight line until it reaches the plates, a rotary beater arranged to receive material passing through said openings, and serrated rolls arranged beyond the heater in position to have the material pass through them.

14. Apparatus for decorticating bast fiber plants which comprises a pair of smooth-surfaced rolls, a pair of serrated or corrugated rolls, a reciprocatory breaker plate arranged between the smooth-surfaced and serrated rolls, and means for feeding the plant stalk into the crushing rolls in a substantially straight line and for maintaining it in a straight line until it reaches the reeiprocatory breaker plate.

15. Apparatus for decorticating bast fiber plants which compilses a pair of smooth-sure faced rolls, means for feeding the plantstalks between said rolls without preliminary bendin a pair of serrated or corrugated rolls, and a pair of relatively. reciprocable plates arranged between the two pair of rolls. said plates having slots substantially in line with the first roll pass.

16. Apparatus for decorticating bast fiber plants which "comprises a pair of smooth-surfaced rolls, means for feeding the plant stalks between said .rolls without preliminary bendin a pair of serrated or corrugated rolls, and a pair of relatively reciprocable plates arranged between the two pair of rolls, said plates havin slots substantially in line with the first r011 of. a pair of smooth-surfaced crushing rolls. a'

pair of slotted breaker plates arranged with their slots substantially in line with the exit side of the crushing rolls, a pair of feed rolls between the crushing rolls and breaker plates, a rotary beater at the exit side of the breaker plates an cent said last-named pair of rolls, and a second 7 pair of longitudinally grooved rolls, said rolls being arranged in sequence so that material passing therethrough is subjected to pressure while being bent up and down and from. side to side.

20. Apparatus for decorticating the bark of bast fiber plants which comprises a pair of iongitudinally grooved rolls, a pair of rolls grooved spirally in one direction, a pair of rolls grooved spirally in another direction and arranged adiacent said last-named pair of rolls, said rolls being arranged in sequence so that material passing therethrough is subjected to pressure while being bent up and down and from side to side.

21. Apparatus for decorticating bast fiber plants which comprises a pair of smooth-surfaced crushing rolls, a pair of plates having openings therethrough arranged at the exit side of said rolls, means for producing relative reciprocation of said plates in a direction to vary the alignment of said openings with respect to the pass of the crushing rolls, and a pair of feed rolls positioned between the crushing rolls and the plates, said feed rolls being located in close proximity to the plates.

22. Apparatus for decorticating bast fiber plants which comprises a pair of smooth-surfaced crushing rolls, a pair of plates having openings therethrough arranged at the exit side of said rolls, means for producing relative reciprocation of said plates in a direction to vary the alignment of said openings with respect to the pass of the crushing rolls, a pair of feed rolls positioned between the crushing rolls and the plates, said feed rolls being located in close proximity to the plates, and means for flailing the material passing through said openings.

23. Apparatus for decorticating bast fiber plants which comprises a pair of smooth-siufaced cmshing rolls, a pair of plates having openings therethrough arranged at the exit side of said rolls, means for producing relative reciprocation of said plates in a direction to vary the alignment of said openings with regard to the pass of the crushing rolls, a pair of feed rolls positioned between the crushing rolls and the plates, and a trumpet guide positioned between the crushing rolls and feed rolls, said trumpet guide terminating in close proximity to the feed rolls.

24. Method or decorticating bast fiber plants which comprises applying pressure progressively longitudinally of the uncrushed plant stalk in a manner to crush the woody portion of the stalk without substantial transverse fracture thereof, and thereafter breaking the woody portion into short lengths and removing substantially all the woody portion without further'application' of crushing pressure.

25. Method of decorticating bast fiber plants which comprises passing the uncrushed plant stalk in a substantially straight line through to pass the material in a straight line beyond the point where the crushing step is completed, and thereafter breaking the woody portion of the stalk'into short lengths and removing substantially all the woody portion.

26. Method of decorticating bast fiber plants which comprises applying pressure progressively longitudinally of the uncrushed plant stalk in a manner to crush the woody portion of the stalk without substantial transverse fracture thereof, and thereafter bending the stalk back and forth to break the woody portion into short lengths and removing substantially all the woody portion without further application of crushing pressure.

27. Method of decorticating bast fiber plants which comprises passing the uncrushed plant stalk in a substantially straight line through smooth-surfaced crushing rolls and continuing to pass the material in a straight line beyond the point where the crushing step is completed, and thereafter bending the stalk back and forth over sharply rounded surfaces to break the woody portion into short lengths and removing substantially all the woody portion.

28. Method of decorticating bast fiber plants which comprises applying pressure progressively longitudinally of the uncrushed plant stalk in a manner to crush the woody portion of the stalk material in a straight line beyond the point where the crushing step is completed, thereafter breaking the woody portion of the stalk into short lengths and removing the fragments by a flailing action, and thereafter bending the bark longitudinally of the plant stalk in a manner to" loosen the woody center portion from the bark and fibers without substantial transverse fracture of the woody portion, thereafter breaking the woody portion into fragments and removing the fragments without further application of crushing pressure, and thereafter subjecting the bark to combined pressure and bending.

33. Method of decorticating bast fiber plants which comprises applying pressure progressively longitudinally of the plant stalk while maintaining the stalk substantially straight from the time the pressure is initially applied until the crushing of the stalk is completed, and thereafter-bending the stalk back and forth without further application of crushing pressure to assist in removal of, the center portion thereof.

34. Method of decorticating bast fiber plants I whch comprises applying pressure progressively without substantial transverse fracture thereof,

a point where the crushing step is completed, thereafter breaking the woody. portion of the stalk int'o'ashort lengths and removing the fragments by action. f

30. Method of decorticating bast fiber plants which comprises applying pressure progressively longitudinally of the plant stalk in a manner to crush the woody portion of the stalk without substantial transverse fracture thereof, thereafter breakingthgivoody portion into short lengths and re novin'g the fragments by a flailing action, the breaking and flailing steps being performed without further application of crushing pressure, and thereafter separating the bark from the fiber, by subjecting the bark and fiber to combined pressure and bending.

31. Method of decorticating bast fiber plants which comprises passing the plant stalk in a substantially straight line through smooth-surfaced crushing rolls and continuing to pass the longitudinally of the uncrushed plant stalk and thereafter bending the stalk back and forth in only one direction at a time and in the absence of crushing pressure.

35. Method of decorticating bast fiber plants which comprises applying pressure progressively longitudinally of the uncrushed plant stalk in a manner to crush the woody portion of the stalk without substantial transverse fracture thereof, and thereafter bending the stalk back and forth in only one direction at a time and in the absence of crushing pressure.

36. Method of decorticating bast fiber plants which comprises applying pressure progressively longitudinally of the plant stalk while-maintaining the stalk substantially straight from the time that pressure is initially applied until the crushing of the stalk is completed, and thereafter bending the stalk back and forth but in only one direction at a time.

3'7. Method of decorticating bast fiber plants a which comprises applying pressure progressively longitudinally of the plant stalk while maintaining the stalk substantially straight from. the time that pressure is initially applied until the crushing of the stalk is completed, and thereafter bending the stalk first in one direction and then in another while advancing the stalk between each bending operation so that the stalk is bent only once at a given point and so that the leading portion of the bent stalk will always remain free. 7

' SYLVES'I'ER L. ST. JOHN. 

